Hugo Marston must figure out what lies hidden inside an old sailor's chest before a 200-year-old blood promise is revealed and claims another life.

In post-Revolution Paris, an old man signs a letter in blood, then hides it in a secret compartment in a sailor's chest. A messenger arrives to transport the chest and its hidden contents, but then the plague strikes and an untimely death changes history.

Two hundred years later, Hugo Marston is tasked with safeguarding an unpredictable but popular senator who is in Paris to negotiate an end to a dispute between France and the U.S. The talks, held at a chateau in the country, collapse when the senator accuses someone of breaking into his room. But theft becomes the least of Hugo's concerns when someone at the chateau discovers a sailor's chest and the secrets hidden within, and decides that the power and money they promise are worth killing for.

But when the darkness of history is unleashed, even the most ruthless and cunning are powerless to control it.

Praise for The Blood Promise:

"Mark Pryor is one of the smartest new writers on the block. His new novel is a doozy."

—Philip Kerr, author of A Man Without Breath, a Bernie Gunther novel

"Pryor seems to have hit his stride in this series, as he adroitly juxtaposes the light banter between Marston and Green with some scenes of intense emotion.... And, all the while, the suspense ramps up. Top-notch mystery in a skillfully delineated Parisian setting."

—Booklist

Praise for previous Hugo Marston novels:

"[I]n Pryor's propulsive second novel starring affable former FBI profiler Hugo Marston…. The engaging characters sweep readers into a suspenseful chase from Pigalle to the Pyrenées."

—Publishers Weekly

"The Crypt Thief is an eerily good read. Mark Pryor has crafted another chilling, complex, and compelling story. Don't start it if you need a good night's sleep!"

—Allison Leotta, author of Speak of the Devil

"A complex puzzle, genuine suspense, and a compelling protagonist—what more can any reader ask for? Oh yeah, a great location: Paris. I'm sold."

—Michael Robotham, author of Say You're Sorry

"Pryor's steady and engrossing debut combines Sherlockian puzzle solving with Eric Ambler–like spy intrigue. With a cast of characters you want to know better. . . ."

—Library Journal STARRED REVIEW and Mystery Debut of the Month!

"A tale of a city that's gritty, utterly real and filled with surprises both horrifying and tender. Much like a baguette, this fabulous story is crusty on the outside, sweet on the inside, and once you've had a bit, you can't wait for more."

—Oprah.com

"Enough intrigue to satisfy every reader…. A fantastic debut!"

—RT Book Reviews

"The Hugo Marston series now belongs on every espionage fan's watch list."

—Booklist